Fluid reforming process



c. E. sLYNGsTAD FLUID REFORMING PROCESS July 16, 1957 Filed June. 5, 1953 cslsva mamon 10A c1-131A emol-1 +o ATTORN EYS M. W. Kellogg Company, Jersey City, N. J., a corporation of Delaware Application June S, 195:37, SerialiNo". 359,864

s claims. (c1. 19e- 50) l This invention relates to an improved hydroforming process involving a heteropoly acid, and more particularly, it pertains to a reforming' process for light" hydrocarbon oils involving a heteropoly acid in which the severity of the operation provides an unusually high yield of liquid productor highl anti-knocltvalue;

Extensive researchk work has been conducted to determine the most favorable process for' reforming light hydrocarbon oils. One basis for evaluating reforming processes involves measuring the quantity of reformed liquid product, at a given octanev level, and this is termed as selectivityf In the case of a heteropoly acid as catalyst for this process, it was found that highy yields of reformedv liquid product or high selectivities are obtained, and these yields under comparable' operating conditions, are higher than a reforming process using a molybdenum trioxide catalyst. In this comparison, all

the experiments were of the fixed' bed type, in which pelleted catalyst was employed. 'In the course of the development, the heteropoly acid was* employed in a huid system, and' quite unexpectedly, it was found by correlation of operating conditions that this catalyst' performs in a manner which is contrary to expected behaviorron the basis of previous experience with other hydrofo'rming catalysts. Normally, it is expected' that the yield of reformedv liquid product decreases with severity of operation. This is to be expected, because normally an increase in severity tends topromote thoseV reactions which result in the production of normally gaseous products and carbon along with a liquid product of high anti-knock value. This invention deals with a method of operating a fluid'v hydroforming system involving heteropoly' acid catalyst. whereby exceptionally liquid productare obtained.

lt is an object of this invention to provide an improved hydroforming process involving a heteropoly acid catalyst'.

Another object of this invention is to provide a reforming process for light hydrocarbon oils in which the yield of reformed liquid product is significantly higher than what is expected for certain severities of operation.

Still another object of this invention is to provide a hydroforming process for nap'htha fractions involving. a heteropoly acid catalyst under such conditions that an unexpectedly high yield of liquid product is obtained for a given range of severity.

Other objects and advantages of this. invention will become apparent from the following' description and explanation thereof. ,l

By means of this invention it is contemplated employing a process which comprises contacting a light hydrocarbon oil with a fluidizedmassv of finely divided heteropoly acid catalyst under suitable reforming conditions including aY severity factor of about 0.5 toaboutl 3.0. The severity factor is obtained by dividing the catalyst to oil ratio, on a weight basis, by the weight space velocity, whichis the pounds of oil feed cliargedl to the reaction United States Patent Op high yields of reformed 2,799,624 Patented July 16, 1957 ICC zone' on an hourly basis per poundl of catalytic material which is present therein. The severity factor is basedY on operating conditions which are very important in determining the degree of severity of a reforming operation. This severity factor can only apply to a reforming procl cess in which catalyst is being circulated from oney proc-y essing zone toy another, for example, from the reactor' to the regenerator and vice versa, otherwise, it has little or no meaning. Further, by reasonk of the circulation of catalyst from one processing zone to another, an average catalyst activity is maintained in the reaction zone, thus eliminating a factor which may bear on the severity of operation.

The heteropoly acid catalyst' can be optionally pretreated with a hydrogen containing gas, with or without the use of small amountsv of water, at an elevated tem-Y perature prior to use in the reforming operation. This treatment can be elfe'cted in the presence of a small amount of water, generally, in the amount of vabout 0.1 to about 15 mol percent, based on the quantity of hydrogen employed, more usually, about 0.5 to 1.0 to about 61.0 mol percent of water, .on the same basis. Under some conditions, it' is preferred to employ about 2 to about 6 mol percent of water, based on the hydrogen charged to the pretreating Zone. The hydrogen containing gas employed for this purpose can be pure hydrogen or a gasVv containing hydrogen in the amount of about 35 to about b y volume'. ,This pretreatment with a hydrogen containing gas is conducted at an elevated temperature in the range of about 750 to about 1200 F., more usually about 875 to about l100v F. In some cases, it is desirable to pretreat at a temperature of about 930 to about l000 F. At the elevated temperature, the pretreatment can be conducted at atmospheric or superatmospherie pressure, e. g., about 50` to about 1000 p. s. i. g. The ratev of hydrogen containing gas employed for this pretreatment is measured on a hydrogen basis, and it involves about l to about 400 standard cubic feet of hydrogen per hour per pound of heteopoly acidcatalyst, preferably about 2 to about 100 standard cubic feet of hydrogen per hour per pound of heteropoly acid catalyst. The hydrogen is measured on' the basis of standard conditions, which involve a pressure of 760 mm. and a temperature of 60 F.

In the practice of this invention, it is contemplated for the hydrogen pretreatment step to employ an upward passage of gaseous materials including hydrogen through the mass of finely divided catalyst at a superficial' linear gas velocity of. about 0.1 to about 50 feet per second, more usually, about 0.1 to about 6 feet per second, and preferably, on a commercial scale, a superficial linear gas velocity of about 1 to about 2.5 feet per second.l The period of treatment may vary considerably depending upon the severity of conditions employed in this operation'. Generally, the pretreatment operation is conducted for a period of about 0.05 to about 10 hours, more usually, about 0.2 to about 24 hours. The conditions specified above can be used for a pretreatmentY operation involving water as well as one in which the hydrogen containing gas is employed in a substantially anhydrous condition. It should be understood, however, that the pretreatment involving a small amount of water ispreferred over the operation involving substantially anhydrous' conditions by vii-tue of the better results obtained thereby. Usually, the'rwater required for the pretreatment ofthe catalyst is added with the hydrogen containing gas. ThisV procedure can be varied by injecting the water or vapor thereof into the mass of catalyst after regeneration as afsepa'rate stream; or the steam or water is fed directly into the' catalys't stream which is flowing from the regenerator to theY pretreating vessel or zone. In some cases, the reduc- 1J ing atmosphere prevailing in the reforming zone is suciently effective for the purpose of activating the catalyst so that little or no benets are derived from a separat treatment.

The feed stock to be reformed by means of the present invention is a light hydrocarbon oil and includes, for example, gasoline, naphtha and kerosene. The light hydrocarbon oil can have an initial boiling point of about 85 to about 325 F. and an end point of about 300 to about 500 F. In the case of reforming a naphtha fraction, it is preferred to employ a naphtha having an initial boiling point of about 100 to about 250 F. and an end point of about 350 to about 450 F. Generally, the light hydrocarbon oil to be reformed has a Watson characterization factor of about 11.50 to about 12.20. Thev feed material can be one which is a straight run or virgin stock, a cracked stock which is derived from a thermal or catalytic cracking operation, or a mixture or a blend of straight run and cracked stocks. Accordingly, the octane number of the feed material can be at least 5 SFRR clear, or more usually, about to 80 CFRR clear and the olefin content of the oil can vary from about 0 to about 50 mol percent. This light hydrocarbon oil can be derived from any type of crude oil, consequently, it can contain sulfur in the amount of 0 to about 3.0% by weight. However, this invention is particularly applicable for light hydrocarbon oils containing at least about 0.1% of sulfur. This sulfur concentration can vary from the minimum up to about 3.0% by weight as indicated above. Generally, feed stocks containing at least 0.1% of sulfur adversely iniluence hydroforrning reactions such that a reduced yield of reforming liquid product is obtained. In the case of the heteropoly acid catalyst, it was found that excellent yields of liquid product are obtained, notwithstanding the presence of at least about 0.1% of sulfur in the feed material, thus indicating that this catalyst is not affected by sulfur to the extent of other hydroforrning catalysts such as, for example, molybdenum trioxide, platinum, etc. This is an important finding, because the processing of high sulfur feed stocks, in some cases, may involve a feed pretreatment in order to remove sulfur to the extent that is permissible for satisfactory commercial operation. Within the range of severities employed in the present invention, other hydroforrning catalysts would be seriously affected in selectivity such that the product yields would be significantly lower than is desired for commercial operation.A Quite unexpectedly, by using the heteropoly acid catalyst under severe operating conditions on feed stocks containing at least 0.1% of sulfur, it was found that the liquid product yield is at an exceptionally high level relative to processes involving other types of catalyst. The light hydrocarbon oil is reformed under conditions which can involve the net consumption or net production of hydrogen. The system involving the net production of hydrogen is referred to hereunder as hydroforrning, and it is operated under such conditions that the quantity of hydrogen produced is enough to sustain the process Without the extraneous use of hydrogen. Irrespective of consumption or production of hydrogen, generally, for this reforming process, the temperature is about 700 to about 1100 F., preferably about 850 to 975 F. The pressure of the operation is generally maintained at a level suitable for the desired hydrogen partial pressure, and this may vary from about to about 1000 p. s. i. g. From the standpoint of liquid product yield, it is preferred to operate the process at a pressure of about 50 to about 500 p. s. i. g. The quantity of oil processed relative to the amount of catalyst in the reaction Zone is measured in terms of the weight space velocity and this was defined above. This weight space velocity can vary from about 0.10 to about 10.0, although, more usually, it is about 0.25 to about 5.0. The Weight space velocity is correlated with the catalyst to oil ratio on a weight basis. As commonly understood, the catalyst to oil ratio is the ratio of the pounds of catalyst being circulated to the pounds of oil being charged to the reaction zone, on an hourly basis. The catalyst to oil ratio for this process can vary from about 0.25 to about 5.0, and more usually, this ratio is about 1 to about 2.5. The severity factor is obtained by dividing the weight space velocity into the catalyst to oil ratio. For a fluidized system involving the circulation of catalyst, the severity factor provides an excellent means for determining the severity of operation. For the purposes herein, the severity can vary from about 0.5 to about 3.0. For certain purposes, it may be desirable to operate this process with a severity factor of about 0.7 to about 2.9.

For this process, it is contemplated adding hydrogen in order to maintain carbon production within a reasonable level. The quantity of hydrogen which is added is usually measured in terms of standard cubic feet (measured at 60 F. and 760 mm.) per barrel of oil feed charged to the reaction zone (1 barrel=42 gallons). This quantity is usually abbreviated as s. c. f. b. On this basis, the hydrogen rate can vary from about 500 to about 20,000 s. c. f. b., and more usually, it will be about 1000 to about 7500 s. c. f. b. Another method of indicating the quantity of hydrogen which can be present in the reaction zone is by means of hydrogen partial pressure and this quantity can vary from about 15 to about 500 p. s. i. a., more usually, about 25 to about 375 p. s. i. a., based on inlet conditions.

In accordance with this invention, the reforming operation can be effected With or without the addition of small amounts of water. The addition of small amounts of water may effect an increase in the quantity of reformed liquid product. Generally, for this purpose, about 0.1 to about 10 mol percent of Water, and more usually, about 0.25 to about 5 mol percent of water, based on the hydrogen which is added to the reforming zone. Under some conditions it is highly desirable to add about 0.5 to about 2.5 mol percent of water, based on the hydrogen which is added to the reforming zone. The deliberate addition of water may serve another purpose in conjunction with the improvement in liquid product yields. It was noted from the use of heteropoly acid catalysts that there is a net production of water in the reforming zone. Further, it was noted that the carbon yield was directly proporltional to the catalyst to oil ratio. Coincident with this fact, it was also noted that the catalyst to oil ratio has a significant eect upon the liquid product yield. Froznthe standpoint of liquid product yield, it is highly desirable to operate the present invention with a catalyst to oil ratio ranging from about 0.8 to about 2.95. High liquid yields are obtained with catalyst to oil ratios of about 1.5 to about 2.5. However, as previously indicated, the higher the catalyst to oil ratio, the greater the carbon production. Consequently, for optimum performance, it is preferred to operate at a low catalyst to oil ratio and obtain the highest liquid product yields. It is proposed by means of the present invention to obtain this effect by adding to the reforming zone a quantity of water which is determined on the basis of the difference in the net production of water between the catalyst to oil ratio at which the high liquid yield is obtained and the catalyst to oil ratio at which a desirable low carbon yield is produced. By this method, the present invention would be operated at catalyst to oil ratio in the range of about 0.1 to about 1 and the quantity of water added to the reforming zone would be sufficient to produce the effect of obtaining liquid product yields corresponding to a catalyst to oil ratio range from about 1 to about 2.75. In effect, the carbon yield would correspond to the actual catalyst to oil ratio; whereas the liquid product yield would correspond to the catalyst to oil ratio which is the equivalent of the actuai catalyst to oil ratio plus the effect of adding a quantity of Water to provide the desired catalyst to oil ratio for the liquid product yield in question. This technique is unusual in that it provides amethod by which high liquid yields are obtained' at relatively low vcarbon production.

Due to ythe reforming operation, the heteropoly acid catalyst becomes contaminated with carbonaceous material which lowers its catalytic activity undesirably. Hence, Ithe catalyst is subjected to :a regeneration treatment which involves contacting the same with an oxygen containing gas, e. g., oxygen, air, diluted air having about 1 to about 10% oxygen lby volume, etc., 'at `a temperature of about 600 to about 1250" F., preferably about 950 iF. to about llSO F. The regeneration is effected at atmospheric pressure or elevated pressure of about 2 -5 to about 1000 p. s. i. g. Prior to regeneration, the catalyst usually contains about 0.1 to about `5.0% lby weight of carbonaceous material, and due to regeneration the carbonaceous material contact is reduced to zero content or up to about Y0.5% by weight. It lis. desirable to remove -as much fcarbonaceous material .as is economical, because such material deposited on the catalyst may undesirably ten-d to cover the active centers of the heteropoly acid catalyst, Iand thus render the catalyst less effective for the reiiorming operation. -In such a case, the ideal situation may 'be to burn off essentially Iall the carbonaceous material deposited on the catalyst.

vlThe heteropoly acid which is employed in the preparation of the catalyst in the present invention is one having at least two different :acid forming elements united in the said functional group. One of the acid forming elements is termed, `for the purposes of this specification and the appended claims, as the central acid forming element, by reason that, generally, another one or more outer acid forming elements are lbound thereto in the ratio of about 3-12 to l of outer acid forming element or elements to central acid forming element or elements, more desirably about 12 to l on a simi-lar basis. For example, the ratio of outer acid forming element -to central acid forming .element occurs in four main classes having ratios of l2, 9, 6 and 3 'to l. The same combination of different elements occur in Imore than one class. The outer acid forming elements will be regarded 'as 'those which are attached to the central acid forming element of Athe acid forming functional group in predominant number. The central acid forming element is any element which is at least trivalen-t and is capable lof forming lan oxygen containing compound which has acid-ic properties, and/ or an analogous thiocompound of :acidic properties in which all or part of the oxygen atoms are replaced by sulfur. The `ou-ter acid forming elements are molybdenum, chromium, tungsten and vanadium. 'It is also contemplated Iemploying heteropoly acid-s in which more than one outer acid forming element is present in the said functional group, als well as more than one centr-al acid forming element is present the-rein. The central acid forming elements are, for example, phosphorus, germanium, tellurium, arsenic, aluminum, boron, silicon, manganese, cobalt, rhodium, chromium, selenium, iodine, platinum, antimony, etc. Specic examples of the heteropoly acids are, for example, molybdenum lacid iodate, H2[I2O4(MoO4)]-1H2O; molybdenum acid selenite, 3SeO2-10M0O3-XH2O; molybdenum acid arsenate,

where-in X is l to 70 and M is a trivalent element selected from Al, Cr, Fe, Co, Mn, or Rh; ammonium salt of aluminum molybdate, (NH4)aHe[Al(MoO4)el-7H2O; m0- lybdenum acid titanate, TiO2l2MoO322H2O; molybdenum ,acid germanate, GeOz-l2MoO3-32H2O; molybdenum acid vanadate, V2Os-8M0O3SH2O; ammonium acid salt of thiovanadate-thiomolybdate,

(NH4) 5H3 [H2 (M084) 4(VS3 2] 10H20 ammonium acid salt of nickelous molybdate,

(NH4) 4H6 [Ni-(M004) s] "5H2O molybdenum acid platinate, PtO2l0MoO3XH2O; chromium acid iodate, 2CrO3-IzO55H2O; ammonium acid salt of phosphovanadate, ('NH4)5H2[P(V2O6)6]-2lH2O; silico-molybdic acid, H4[SiM-o12O4o]-XH2O, wherein X can be 5 to 29; phosphomolybdic acid,

aluminomolybdic acid, H1o[Al(!M-oO4)e]-10H2O; and periodotungstic acid, llzO'rlZWOallHzO. The heteropoly acids can be derived 'from the corresponding ammonium salts under .reaction conditions, consequently, .such salts can be used as precursor materials for the purpose of this invention. Furthermore, it should be understood, -for the purpose of this specication and the appended claims, that the term heteropoly acid is intended :to include the use of those materials which will, under reaction .condi-tions, convert to the active acid form. The fheteropoly .acids are generally in the hydrated form, however, it :should be understood that these acids are useful in any state of hydration, lalthough the higher hydra-tes :are ymore :satisfactory by reason that usually such acids contain high ratios of outer .acid yforming element to central acid forming element.

The heteropoly acid Ior mixtures thereof can be used alone, or 4they are supported on carrier materials, such as for example, zinc spinel, alumina, silica, magnesia, titania, zirconia, silica-alumina, -alumina-ma-gnes'ia, alumina- .titania, pumice, fullers earth, kieselguhr, bentonite clays, SuperltroL bauxite, alumina-thoria, charcoal, etc. Any support or carrier lmaterial may 'be useful r.for the catalyst, provided it does not catalyze the undesired reac- :tions to any great extent. Generally, about .5 lto -about 50% by weight, preferably about 4 t-o about 20% 'by weight of heteropoly `acid `or mixtures thereof are employed, based on the total catalyst. It is desirable to add 1a small amount of silica, i. e., about 0:1 to abou-t 12% 'by weight based on the total catalyst, in order -to enhance catalyst stability at elevated temperatures, particularly in the case of using alumina as a support. The alumina can be in the gel or .activated form as either etaor gamma-alumina orl mixtures of the two.

Having thus provided a general Idescrip-tion of the :above invention, reference will be 'had to the accomfpanying `drawings which will illustrate this invention in a amore spec'ic manner.

Figure l is a `schematic illustration of the uid pilot ,plant in which the present invention was evaluated; and

Figure 2 is a .correlation of lthe liquid product yield and the severity factor.

In Figure 1,the reaction vessel 5 is a vertical, cylindrical vessel having an internal diameter of 3 inches and a length of 36 feet. Superimposed on reactor 5 is a lilter housing 7 which Ais a vertical, cylindrical section of enlarged cross-sectional area and a gradually reduced section 9 connects it with the top of the reactor. Filter housing 7 contains -lters (not shown) which serve to remove ,entrained finely divided catalyst from the etliuent product stream. The product material is discharged from the top of the filter housing through a line 11, and the product material is passed to a product recovery system (not shown). The temperature of the reaction zone was indicated by a series of thermocouples spaced along the length of the reactor, approximately 5 feet apart. These thermocouples are not shown in the drawing. Spent catalyst is withdrawn continuously and directly from the fluidized bed in the reaction Zone through a transfer line 15 which is connected to the reactor at a distance of about 121/2 feet from the bottom end thereof. A suitable control valve 17 is installed in the transfer line 15 for the purpose of automatically regulating the flow of catalyst therethrough. The spent catalyst passes through the transfer line 15 and discharges into a stripper standpipe 19. The stripper standpipe 19 is about 31 feet in length and has an internal diameter of about 1 inch. In the bottom of the stripper standpipe 19, there is installed a control valve 21 for the purpose of automatically controlling the llow of catalyst from the standpipe into a lift vessel 23. Stripping steam is admitted into the stripper standpipe through a line 25 and this gas inlet is situated about 10 feet from the bottom of standpipe 19. superimposed on standpipe 19 is a stripper 27 which is a vertical, cylindrical vessel having a length of l feet and an internal diameter of 2 inches. The stripper products are removed from the top of stripper 27 through a valved line 30 which is connected to the top part of lter housing 7 of the reactor vessel. The stripper 27 contains spent catalyst and the lter system of the reactor serves to separate the entrained catalyst from the stripper products. The stripped catalyst is discharged from standpipe 19 into the lift vessel 23 previously mentioned. To the bottom end of the lift vessel which is inclined at a suitable angle from a vertical axis, there is admitted air through a line 32. This air stream serves to carry the stripped catalyst as a suspension into the bottom end of the regenerator 34 through a transfer line 36.

The regenerator 34 is a vertical, cylindrical vessel having a length of 23.5 feet and an internal diameter of 3 inches. There is superimposed on the regenerator 34 a iilter housing 33 which is connected to the top of the regenerator by means of a reducing section 40. The filter housing 38 contains suitable lters for the removal of entrained catalyst from the flue gas eiuent. The flue gas substantially free ot catalyst is discharged from the filter housing through a valved line 42. Suitable thermocouples are situated along the length of the reactor 30 for the purpose of indicating the regeneration temperature and these are not shown in the drawing. The regenerator 34 superimposes the regenerator standpipe 44, which is vertical, cylindrical vessel having a length of 20 feet and an internal diameter of 1 inch. In the bottom part of the regenerator standpipe 44, there is situated a control valve 46 which serves to control automatically the ow of catalyst from the standpipe to the bottom part of a second lift vessel 48. Preheated oil feed and recycle gas containing the desired amount of hydrogen are supplied to the bottom end of lift vessel 43 through lines 50 and 52, respectively.

The combined oil feed and recycle gas serves to transi port the regenerated catalyst as a suspension through a transfer line 54 and this gaseous suspension is admitted into the bottom end of reactor 5.

In operation, vaporized oil feed and recycle gases are preheated to a suitable temperature of about 800 to about l200 F. and they are admitted into the regenerator lift vessel 48, thereby serving to carry the regenerated catalyst at the desired catalyst rate to the bottom of the reactor. The regenerated catalyst contains, on the average, a carbon content of about 0.02 to about 0.15% by weight of carbon. The temperature of the reactor was maintained by means of external heaters circumscribing the reactor. The reactant materials passed upwardly through the reactor at a superficial linear gas velocity of about 0.1 to about 1.0 foot per second. The catalyst bed was maintained at a height of about to about 35 feet. The spent catalyst was withdrawn from the reactor in the manner indicated above and it usually contained about 0.5 to about 5.0% by weight of carbon. The spent catalyst was stripped in the stripper standpipe 19 and stripper 27 by means of steam which was admitted at the rate of about 2 pounds` per hour through line 25. The temperature in the stripper was'maintained at about 900 to about 9509 F. The stripped catalyst was discharged from the bottom of standpipe 19 into the stripper lift vessel 23, and it was carried by means of air, supplied through liney 32, to the bottom of regenerator 34. The air stream was maintained at a temperature of about 700 to about l000 F. The temperature in the regenerator was maintained at about 950 to about 1100 F. and the iluidized bed at a height of about 5 to about 20 feet. The regenerated catalyst was discharged from the bottom of the regenerator standpipe into liftv vessel 48 from which it was transported as a gaseous suspension to the bottom of the reactor. v

Feed stocks employed for the purpose of this evaluation are given below in Table I.

Table I Feed Designation A B Gravity, AP1 51. il 52. 9 ASTM Distillation, "F

I. B. P 200 240 237 283 245 292 255 209 264 308 271 315 280 321 287 328 293 336 301 345 314 360 324 372 344 387 113 135 5l. 2 25. 9 15. 5 14. 9 Olefms, Mol percent 1. 7 1. 1 Sulfur, Wt. percent 0.23 0. 104 Refractive Index 1. 4288 Watson Factor 11.70 11.99 Molecular Weight 118 135 The catalyst employed in this evaluation was prepared by reacting stoichiometric proportions of molybdenum trioxide and phosphoric acid to produce an aqueous solution of phosphomolybdic acid, and this acid was used to impregnato alumina (this alumina is commonly known as Nalcat) to produce a finished catalyst, having about l0% by weight of phosphomolybdic acid. Following the impregnation of the alumina with the phosphomolybdic acid, the catalyst was dried at a temperature of about 210 to 240 F., and then it was calcined for a three hour period at 1000 F. For the purpose of the tables presented hereinbelow, this catalyst is represented as 1. The feed stock containing about 0.1% of sulfur was evalnated under various conditions of severity in order to determine the effect on liquid product yield. These data are presented in Table Il below.

Table Il Run No 1 2 3 4 5 6 Feed B B B B B B Catalyst I I I I I I Operating Conditions:

Temperature, F 930 940 930 930 930 030 Pressure, p. s. 1. g 250 250 255 255 250 250 Reiycle Gas, S. C. F.

5 340 5 140 5 040 5,040 5,120 5,4 Mol percent H2 in y y 30 Gas 54. 4 51.0 54. 4 54.4 54. 8 59.2 Space Vel., Wn/hn/Wc. 1. 1 1. 1 0.52 0.52 1. 0 0.99 O/O ratio 2. 4 0. 8 2.9 1. 8 5. 6 4,3 Y Severity Factor 2.15 0.72 5. 57 3.46 5.60 4. 34 Yields (Output Basis):

05+ Itnquld, Vol. per 83. 3 82. 3 74. 1 30. 0 75. 7 78. 9

een Polymer, Vol. percent 1. 8 1. 5 2.0 2. 0 2. 2 2. 1 Butanes, Vol. percc11t 5. 2 5. 3 7. 3 6. 2 7.0 G. 5 Dry Gas, Wt. percent. 7. 4 10. 4 12.6 9. 8 10. 6 9. 6

In order to demonstrate the eiect of the severity factor on liquid product yield, a correlation was drawn and this 1s presented in Figure 2 of the attached drawings.

It is noted from Figure 2 that the liquid product yield increased with severity from a severity factor of about 0.5 to about 3.0. Thereafter, it declined as one would expect by reason of the usual degradation to normally gaseous product and carbon. The increase in liquid product yield with severity is quite unexpected in view that normally one expects to obtain a decrease in yield of reformed liquid product with increase of severity. A

Another feed stock was evaluated under the severity falling within the range shown in Figure 2 in order to determine the applicability of this proposition to the feed stocks of high sulfur content. T'hese data are presented in Table III below.

Table III Run No 1 2 Catalyst. I I Feed l. .A B Pressure, p. S. i. g 250 255 Temperature, F 925 930 Recycle Gas, S C F B 5, 910 5, 040 M01 Percent H2 in Gas 60. 5 54. 4 Space Vel., WolhL/Ws- 0.6 0.52 C/O ratio 1.4 1.8

86.3 80.0 1. 2 2.0 3. 7 6. 2 Dry Gas, Wt. Percent.. 6.9 9. 8 Carbon, Wt. Percent 1. 1. 4 CFRR clear-Octane No. 06+ Gasolinel 90.1 90. 4

1 400 F. end point.

It is noted from Table III above that a feed stock containing about 0.23% of sulfur responded with an unusually high yield of liquid product to a severity falling within the range of the present invention. This substantiates the finding that the present invention is unusually applicable for feed stocks containing at least about 0.1% of sulfur.

Having thus described the present invention by reference to specific examples thereof, it should be understood 10 that no undue limitations or restrictions are to be imposed by reason thereof, but that the scope of the invention is defined by the appended claims.

I claim:

1. A process which comprises contacting a light hydrocarbon oil with a dense iluidized mass of finely divided heteropoly acid catalyst containing molybdenum as the outer acid forming element, at a temperature of about 850 to about 975 F., at a pressure of about 50 to about 500 p. s. i. g., in the presence of added hydrogen in an amount of about 1000 to about 7500 s. c. f. b., a weight space velocity of about 0.25 to about 5.0, a catalyst to oil ratio of about 1 to about 2.5, and such that the severity factor is between about 0.7 and 2.9.

2. A process which comprises contacting a light hydrocarbon oil with a uidized mass of finely divided phosphomolybdic acid catalyst under suitable reforming conditions including a catalyst to oil ratio of about 0.8 to about 2.95, a weight space velocity of about 0.10 to `about 10.0, such that the severity factor is about 0.5 to

about 3.0.

3. A process which comprises contacting a naphtha fraction with a dense fluidized mass of finely divided phosphomolybdic acid on alumina catalyst, at a temperature in the order of about 930 F., a pressure of about 250 p. s. i. g., in the presence of added hydrogen in the amount of about 5340 s. c. f. b., a weight space velocity of about 1.1, a catalyst to oil ratio of about 2.4, and such that the severity factor is about 2.18.

References Cited in the Ele of this patent UNITED STATES PATENTS 2,303,083 Kuhl Nov. 24, 1942 2,320,147 Layng et al. May 25, 1943 2,547,380 Fleck Apr. 3, 1951 2,608,534 Fleck Aug. 26, 1952 FOREIGN PATENTS 689,005 Great Britain Mar. 18, 1953 

2. A PROCESS WHICH COMPRISES CONTACTING A LIGHT HYDROCORBON OIL WITH A FLUIDIZED MASS OF FINELY DIVIDED PHOSPHOMOLYBDIC ACID CATALYST UNDER SUITABLE REFORMING CONDITIONS INCLUDING A CATALYST TO OIL RATIO OF ALBOUT 0.8 TO ABOUT 2.95, A WEIGHT SPACE VELOCITY OF ABOUT 0.10 TO ABOUT 10.0, SUCH THAT THE SEVERITY FACTOR IS ABOUT 0.5 TO ABOUT 3.0. 